The present invention relates generally to a vehicle rollover sensor and more particularly to a magnetoresistive rollover sensor.
Automotive vehicle design is often guided by a variety of factors and concerns. Significant among those concerns has been the safety of the driver and passengers. Numerous safety related components and features have been developed for use in modern vehicles for the purpose of improving the vehicle performance and safety.
These components and features often work in concert with the vehicle to provide a defense against passenger injury. Their form, design, and individual application must often relate to the vehicle performance and handling characteristics in order to function optimally. Thus an intimate knowledge of vehicle handling and performance characteristics may be fundamental to not only specific safety feature performance, but to the overall safety characteristics of the vehicle as a whole.
Such has been the case involving vehicle roll-over. The popularity of vehicles with higher centers of gravity has lead to an increased interest in the prediction of vehicle roll-over as well as to the design of safety features designed to reduce the risk of injury due to roll-over. Both of these design concerns are served by the use of rollover sensors. Roll-over sensors, positioned within the vehicle, can be utilized by design engineers during testing to evaluate the roll-over characteristics of vehicle designs during a wide variety of testing procedures. Precise knowledge of roll-over angles can assist design engineers in evaluating the safety of a vehicle, as well as assist them in the design modifications to improve such safety characteristics. These same sensors can additionally be utilized during vehicle operation in concert with safety features to both reduce the risk of roll-over, as well as protect passengers should such a roll-over occur. Again, the efficacy of such safety features can be optimized with an improved knowledge of a vehicles absolute roll angle.
Present roll-over sensors, however, often utilize systems that fail to provide the accurate roll angle information desired by both designers and safety systems. Often such systems only indicate when a predetermined angle has been exceeded while failing to provide the actual vehicle roll angle. Other systems, while attempting to provide an actual vehicle roll angle do so with a degree of accuracy that could be improved upon. Vehicle motion and momentum during testing and operation can adversely effect some known systems and thereby further decrease their accuracy. It would therefore be highly desirable to have an improved roll-over sensor for use in a vehicle that would provide a vehicle""s absolute roll angle with improve accuracy such that vehicle design as well as the design of safety systems could be better served.
It is, therefore, an object of the present invention to provide an improved vehicle rollover sensor. It is a further object of the present invention to provide a an improved vehicle rollover sensor utilizing a magnetoresistive sensor.
In accordance with the objects of the present invention, a vehicle rollover sensor is provided. The vehicle rollover sensor includes a movable member free to rotate about a single axis. The movable member includes an inertial mass. A magnet is mounted to the movable member. The vehicle rollover sensor further includes a magnetoresistive sensor capable of sensing changes in the magnetic field due to changes in the orientation of the moveable member.
Other objects and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.